Tested 125% of NOS tubes. Very nice, super strong, perfectly balanced tubes with a lot of life left in them.
Tested also for hum and microphonics in RIAA preamp.
Made in famous Heerlen, Holland plant in 1966. The same etched DELTA codes!
Pull outs from professional backup device.
They are tested with 250V on anodes and -1.5V on grids, 100% is 2.15 mA, their measurements (2.6/2.6) (2.6/2.8) mA